Examples of known molding systems are (amongst others): (i) the HyPET™ Molding System, (ii) the Quadloc™ Molding System, (iii) the Hylectric™ Molding System, and (iv) the HyMet™ Molding System, all manufactured by Husky Injection Molding Systems Limited (Location: Bolton, Ontario, Canada; www.husky.ca).
U.S. Pat. No. 5,865,237 (Inventor: SCHORGHUBER et al; Published: 1999, Feb. 2) discloses production of molded foamed metal parts, in which a compacted powder metallurgical preform is foamed by heating in a chamber and the foam charge is injected into a mold.
U.S. Pat. No. 5,972,285 (Inventor: KNOTT; Published: 1999, Oct. 26) discloses a foamed metal especially aluminum body production from a compacted mixture of metal powder and magnesium hydride blowing agent.
U.S. Pat. No. 6,733,722 (Inventor: SINGER et al; Published: 2004, May 11) discloses production of a molded body from a foamed metal that includes feeding two powders in non-compact form to an extruder, injecting powder mixture into the mold and releasing the pressure so that the mold is completely filled with foamed metal.
PCT Patent Number WO/04108976A2 (Inventor: KÖRNER et al; Published: 2004, Dec. 16) discloses foamed metal molding production, that includes adding foaming agent to molten metal after leaving supply vessel and before entry into a mold cavity. Also disclosed is a method for producing a metal foam body, whereby a molten metal is prepared and introduced into a reservoir, and the molten metal is injected into a mold cavity surrounded by a mold, via a line connecting the reservoir to the mold. The aim is to create a foam structure only in the core of the metal foam body. To this end, a blowing agent is added to the metal melt, once it has left the reservoir and before it enters the mold cavity.
U.S. Pat. No. 6,866,084 (Inventor: ASHOLT et al; Published: 2005, Mar. 15) discloses a method and means for producing molded bodies of a metal foam, in particular an aluminum foam. The method involves the use of mold having a cavity and at least one entrance opening. The mold is filled with a metal foam in a manner where the entrance opening of the mold is submerged into a metal melt and the melt is caused to foam inside the mold and fill its cavity.
U.S. Pat. No. 6,840,301 (Inventor: NICHOL et al; Published: 2005, Jan. 11) discloses aluminum article casting that involves releasing pressure in a bath, after filling a molten aluminum foam produced by passing gas bubbles through the molten aluminum, to remove the article from the die cavity.
U.S. Pat. No. 6,915,834 (Inventor: KNOTT et al; Published: 2005, Jul. 12) discloses production of a metal foam that includes inserting the molten metal into a mold hollow chamber, and foaming with a propellant which is solid at room temperature. Also disclosed is a process for producing a metal foam and to a metal body produced using the process. The object is achieved by a process for producing the metal foam by adding a blowing agent to a metal melt, wherein the metal melt is: (i) introduced into the die cavity of a metal die-casting machine, and is (ii) foamed using a blowing agent, which releases gases and is solid at room temperature.
U.S. Pat. No. 6,998,535 (Inventor: NICHOL; Published: 2006, Feb. 14) discloses a method for casting articles from a metal foam, a molten metal bath and a foam-forming means. The foam is drawn into a ladle, within a heated chamber, which transports a foam sample to a mold. The ladle deposits the foam sample into the mold and the mold is closed. Once cooled and hardened the formed article is removed. The system includes a molten metal bath, a heated foam collecting chamber, a ladle for drawing a sample of the foam and for transporting the sample to a mold.
PCT Patent Application Number WO/06021082 (Inventor: KILLINGBECK et al; Published: 2006, May 04) discloses a casting apparatus for casting metal foam article from foam of molten metal. The apparatus includes a gas injection nozzle connected to a gas supply. The nozzle is positioned below a mold cavity opening. A flow generating mechanism causes a molten metal to flow.
U.S. Pat. No. 7,175,689 (Inventor: DOBESBERGER et al; Published: 2007, Feb. 13) discloses a process for producing a lightweight molded part, comprising introducing a gas into a particle-containing, molten metal to produce a metal foam having voids with a monomodal distribution of their dimensions, introducing the metal foam into a casting die and compressing it therein essentially under all-round pressure; and the molded part made by this process.
U.S. Pat. No. 7,195,662 (Inventor: DOBESBERGER et al; Published: 2007, Mar. 27) discloses a device for feeding gas in a melt of foamable metal by means of at least one pipe for producing metal foam. The gas insertion pipe projects inwardly into the melt and at the projecting end has a gas outlet having a cross-sectional area of 0.006 to 0.2 millimeters (mm) squared, and a pipe face area of less than 4.0 mm squared. A flowable metal foam has gas bubbles defined by walls of a liquid metal matrix with solid reinforcing particles, and the diameter of the largest gas bubbles divided by that of the smallest gas bubbles is less than 2.5.
A technical article (Title: METALLIC FOAMS—ULTRA LIGHT MATERIALS FOR STRUCTURAL APPLICATIONS; Author: FRANTIEK SIMANCIK; Technical Journal Name: INZYNIERIA MATERIALOWA Nr. 5/2001; Pages: 823 to 828) discloses, in the Abstract, the following: metallic foams are relatively unknown structural materials, however with enormous future potential for applications where lightweight combined with high stiffness and acceptable manufacturing costs are of prime interest The performance of metallic foams, in particular those made of aluminum, in various prototypes, such as foamed panels, sandwiches, complex 3-D-parts, foamed hollow profiles as well as castings with foamed cores, has been discussed with respect to the expected and achieved goals. The important contributions of aluminum foam to the improvement of the products properties are highlighted and most promising utilization is suggested.
A technical article (Title: PRODUCTION AND PROPERTIES OF FOAMED MAGNESIUM; Authors: Fr.-W. BACH, 0. BORMAUN, P. WILK, R. KUCHARSKI; Journal Title: CELLULAR METALS AND POLYMERS 2004, pages 77 to 80, edited by R. F. Singer; C. Körner, V. Altstadt, Fragezeichenverlag, Furth, Long ISBN number 8585858585) discloses, in the Abstract, results from the priority program “Cellular Metals” of the Deutsche Forschungsgemeinschaft (DFG SPP 1075). Two processes for the production of foams and sponges basing on magnesium are presented and discussed concerning their producibility and their applications. The powder metallurgical route for the production of metallic foams basing on aluminum is well examined since some decades but foamed parts basing on magnesium could not be produced yet. The discussion of the foamability of magnesium alloys leads to a sintering process which enhances the foamability at the beginning of the foaming process and finally leads to foamed magnesium cylinders with 40 mm in diameter. Relatively easy in the production but appropriate only for small open cell sponges is the infiltration process using salt grains as place holder. The molten magnesium is forced by vacuum to infiltrate the salt grains which are dissolved in sodium hydroxide solution after machining. A method which applies mechanical vibration for grain fining of the bulk material and improving the infiltration process is adopted.